Real Time Water Quality Monitoring on Rivers

Long term water quality monitoring on rivers can be an arduous chore; and very expensive.  The cost of sending teammates into the field continues to skyrocket, especially when it is over water; not to mention the inherent safety concerns. All this for what amounts to a ‘snap-shot’ of water quality at the time of measurement…

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Parshall Flumes – Free vs. Submerged Flow

As often as we use Parshall flumes for open channel flow measurement, it is important to understand “free versus submerged flow” conditions; as it greatly impacts the accuracy of the installation…or the lack thereof. While any primary device could be affected by submerged flow conditions, there isn’t much data to be found on the topic.…

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The Thelmar Weir – Insertable Volumetric Weir for Flow Measurement in Pipes

Thelmar Insertable Volumetric Weirs are commonly used for temporary flow measurement in a pipe, or manhole; with relatively low flows.   The Thelmar weir is calibrated compound weir that is inserted into the invert of a pipe and incorporates a 90° v-notch for measuring lower end of the range; then opens into a rectangular weir at…

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Criteria for Proper Weir Design

The sharp-crested weir is probably the most common open channel primary device we find for measuring flow.  It is basic, and usually, the least expensive design option. While most weir installations we encounter do perform well, they are too often outdated, misapplied, or not maintained for present flow conditions.  Many of our customers are surprised…

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Flow Measurement Solution….The H-Flume

Recently, an industrial plant needed an accurate means to measure flow from a tank.  Since most commonly used flow equations for weirs rely on a sharp-crested weir plate, the thick tank sidewall presented an issue.  We were uneasy with assumptions, no flow chart, and exactly how to convert level to flow rate.  Too, windy conditions…

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